For the past week or so I thought I was going crazy. I have been hitting mobs for 100 (barely) Sinister Strikes at level 47. My 5 point eviscerates land for 220-230 on average. After finally seeing some other questions/concerns from melee players in general chat I decided to do some research. I am 100% certain damage is not correct for at least melee players right now. I'm not sure if the problem is with how mobs are coded/setup or with player damage (probably the former).
I have been running around trying to fight every different type of mob, and I finally found some (elementals) to which I can do normal damage. Interestingly enough, these are the thistleshrub rootshapers and dew collectors; however, against the gnarled thistleshrubs, my damage is extremely low (about half of what it should be). This makes it hard for me to identify the exact problem, but there's definitely something wrong.
Against most mobs, especially humanoids and beasts, it seems my damage is half of what it should be. Eviscerates hit for 220-240 instead of 450-470. SS hits for 100 instead of 180-220. Autoattacks are also at half.
I did not see this reported anywhere else after a forum search so I am hoping to see if others can chime in with their observations. I will probably dust off fraps and get a video of this unless someone points out that this is already a known problem or whatever.